Light and darkness are the most important timekeepers of our internal clock. The reason for this is special receptors in the retina of the eye. They are sensitive to light and regulate biological processes in the body when light falls on them - including our biorhythm. When daylight hits these ganglion cells, it wakes us up and switches the body to "activity". At the same time, the production of the happiness hormone serotonin is boosted.
Darkness leads to the release of the sleep hormone melatonin and makes us tired. If our body receives too little light, the hormone balance between melatonin and serotonin is disturbed. Poor sleep and sleep disorders can be the result. Natural light and sunlight therefore not only have a significant influence on our well-being and our mood, but also significantly shape our biorhythm and thus our sleep.
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We sleep so that our body can relax and the mind can process the experiences of the day. During sleep, reactions to external stimuli are reduced. Blood pressure, heart rate, metabolism, breathing and body temperature decrease. A restful night with sufficient sleep is extremely important for our physical and psychological well-being.
Sleep serves for recovery, regeneration, repair of all organs, tissues and cells and replenishes our energy stores. In sleep, we process newly gained experiences and impressions more intensively than during the day. Those who sleep well lose weight more easily and improve their mental and physical fitness. In addition, restful sleep strengthens the immune system, emotional balance and better organ and metabolic functions.
Sleep problems and sleep disorders can bring with them a variety of physical and psychological consequences. Studies show that lack of sleep leads to a deteriorated carbohydrate metabolism, among other things.*1 Blood glucose levels are increased and the production of the pancreatic hormone (insulin) is disrupted. This can also promote insulin resistance, which can trigger diabetes. Poor sleep is a cause of a host of other health problems.
Possible symptoms that can occur due to poor sleep:
In times when there was neither electric light nor an alarm clock, people lived according to the dictates of nature. They went to bed when it got dark and got up when the sun rose. This is how our internal clock has been ticking since time immemorial. The timekeeper of our daily routine has therefore always been the rotation of the earth and the change between daylight and darkness. In addition, most tasks consisted of physical work that took place outdoors. Today, the majority of us work in closed rooms, which means we receive less daylight and sunlight than is good for us.
A lack of natural light has a significant influence on the balance of the body's own hormones melatonin and serotonin and therefore on our day-night rhythm. Melatonin is referred to as the sleep hormone and significantly influences the quality of our sleep. It makes us tired and promotes falling asleep. The pineal gland mainly releases the hormone in darkness. The longer it is dark, the more melatonin is produced. Serotonin is considered a happiness hormone, energises us and positively influences our mood.
However, the two hormones are by no means just opponents, as they are closely interdependent. Melatonin is largely formed from serotonin in the pineal gland. If our body receives too little light, the hormone balance between melatonin and serotonin is disturbed. Sleep problems, daytime sleepiness and decreased performance can be the result.
Especially on dark days and when little natural daylight and sunlight is available for our body, this internal balance quickly becomes unstable and our general well-being is negatively affected. This is exactly where light therapy (Bright-Light-Therapy), with special daylight therapy lamps and daylight lights, comes in.
Circadian rhythms are internal cycles with a period length of about 24 hours in chronobiology. In most organisms, these processes have a significant influence on internal functions and mechanisms. For example, they ensure that flowers open and close at the right time of day and prevent nocturnal animals from leaving their shelter in daylight, where they would be exposed to enemies more often.
The most distinct expression of the circadian rhythm in humans is the sleep-wake rhythm - our "internal clock". Ideally, our sleep-wake rhythm is designed to provide us with an optimum of sleep and regeneration during darkness and an optimum of performance during brightness. The main timekeeper of this internal clock is light - more precisely, the appropriate interplay of daylight and darkness. If we get enough daylight during a stable light-dark cycle, this has a positive effect on our biorhythm and thus on our sleep. The reason for this are ganglion cells in the retina of the eye. They are light-sensitive and regulate biological processes in the body, such as our internal clock, when light falls on them.
But not all light is the same. To positively influence our sleep-wake rhythm and thus improve our sleep, a light intensity is recommended that corresponds to that of natural daylight. Conventional electric lamps and bulbs have a much lower light intensity and are therefore not able to simulate daylight.
Daylight lights provide a remedy, supplying you with an extra portion of near-natural light even on light-poor days. Daylight therapy lamps have a light intensity of 10,000 lux and cover the colour spectrum of daylight very well. This makes them have a similarly positive effect on our body as natural daylight and are perfect for effective light therapy.
Do you want to learn more about light therapy using daylight therapy lamps?
>> Here you can find the article Light Therapy with Daylight Therapy Lamps
Circadian sleep-wake rhythm disorders refer to a whole group of sleep disorders. They occur when our sleep-wake rhythm is no longer adapted to the external change of brightness and darkness and the given social demands. The result is a disturbance of our internal clock, which signals us when it is time to go to sleep and get up again.
A disturbed circadian sleep-wake rhythm can lead to a variety of sleep problems. The sleep disorders range from problems falling asleep and staying asleep to shallow and poor quality sleep. In addition to the health problems and risks that poor sleep brings, a wrongly set circadian rhythm can also significantly affect our everyday life.
Poor sleep often affects our social contacts, our performance and our leisure activities. The "International Classification of Sleep Disorders" distinguishes the following types of sleep-wake rhythm disorders*2:
Light therapy with the help of daylight therapy lamps can help you successfully reset a disturbed day-night rhythm and improve your sleep.*3
A short-term sleep disorder that probably almost all of us know is "jet lag". This disruption of the circadian rhythm usually occurs after long-haul flights. Due to the rapid journey across several time zones, the change between light and darkness no longer matches our biorhythm and is initially perceived by our body as "wrong".
As a result, our internal clock becomes decoupled from the local time and our natural body processes such as sleep and wake phases, meal times, hormone production or body temperature get out of sync.
To get your biorhythm used to the new day-night cycle as quickly as possible, daylight at the destination will help. Either through natural light outdoors or through a light shower with the help of a daylight therapy lamp. At the same time, it is recommended to adjust your own sleep phases directly to the light and dark phases on site.
Shift worker disorder primarily affects individuals who work persistently at night or are exposed to a constant change in day rhythm due to rotating work shifts.
Regular disruption between personal day-night rhythm and the natural change of daylight and darkness occurs due to night work. Light at the wrong time of the rhythm is a crucial point that makes shift work unhealthy. Many affected individuals complain about other physical ailments such as reduced performance, headaches or digestive problems in addition to sleep problems.
With the help of additional daylight at the workplace and reduced light exposure at bedtime, an artificial circadian rhythm can be created. This can help improve daytime sleep, especially with regular night work.
Circadian sleep phase disorder is divided into delayed sleep phase syndrome and advanced sleep phase syndrome.
In delayed sleep phase disorder, a person's sleep-wake rhythm is delayed compared to the external day and night cycle. Those affected often manage to fall asleep later than desired. At the same time, they find it very difficult to get up in the morning.
Therapy for this sleep disorder recommends minimising light in the evening to boost melatonin production and find it easier to fall asleep. In parallel, light therapy in the morning supports wakefulness and helps to start the day more vitally.*4
People with advanced sleep phase disorder tend to become tired earlier than desired and wake up particularly early in the morning. Here, light therapy in the evening can delay melatonin secretion and gradually normalise the sleep rhythm.*5
This sleep disorder is quite rare as it mainly affects blind people. The reason for this is that blind people are only limited in their ability to receive light-based stimuli for their internal clock. Those affected are unable to adapt to the usual day-night rhythm and fall asleep at "normal" times.
In addition, the sleep-wake rhythm of the individuals is longer than 24 hours. As a result, the sleep times continuously shift a bit backwards.
Even with this circadian rhythm disorder, sleep medicine recommends light therapy in the morning and little light in the evening to stabilise the circadian rhythm.*6
People with this sleep disorder have no regular sleep pattern. In a period of 24 hours, those affected sleep three times or more, at different times and over different time spans. Light therapy during the day is also recommended for this sleep disorder to stabilise the biorhythm again.
Light therapy with the help of daylight therapy lamps can help you successfully reset an out-of-balance day-night rhythm and improve your sleep. The Beurer daylight therapy lamps with a lighting intensity of 10,000 Lux, are perfect for medically effective light therapy.
The use of our daylight therapy lamps is simple and straightforward. Moreover, the use can be easily integrated into your everyday life.
Light therapy using a daylight therapy lamp can generally be carried out as often as desired. For effective application, we recommend using the lamp for at least seven consecutive days. The most effective time of day for treatment is between 6 am and 8 pm depending on the therapy focus. However, it may be useful to schedule the application time for the morning or evening hours.
To start the day fit and vital, for example, the use of the daylight lamp immediately after getting up is recommended. This also boosts serotonin formation.
Evening use of the light box can delay melatonin secretion and prevent premature tiredness. Try it out and bring your internal clock back into balance with the Beurer daylight therapy lamps.
Wake-up lights can help you fall asleep. The light simulation of a sunset has a calming effect on our mind and helps us to switch off. The wake-up light promotes the slow transition from wake mode to sleep mode through gentle sleep melodies.
After a restful night, the Beurer wake-up lights provide an optimal start to the day. Through the simulation of sunrise, our wake-up lights support relaxed waking up even during the dark season. Invigorating wake-up melodies like bird chirping or your favourite radio station help you start the day actively. This is how natural waking up in harmony with your sleep rhythm works.
*1 http://www.pharmazeutische-zeitung.de/index.php?id=37711
*2 https://academic.oup.com/sleep/article/30/11/1460/2696877
*3 https://www.aerzteblatt.de/archiv/225771/Psychische-Erkrankungen-Die-innere-Uhr-tickt-nicht-bei-jedem-Menschen-gleich
*4 https://epub.uni-regensburg.de/20223/1/ubr07803.pdf
*5 https://epub.uni-regensburg.de/20223/1/ubr07803.pdf
*6 https://www.aerztezeitung.de/Medizin/Mehr-Aufmerksamkeit-fuer-die-innere-Uhr-304596.html
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The content of the Healthguide is intended to provide assistance and information and can in no way replace the advice of a doctor.
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